Friction clutch and brake mechanism



Jan 23, 1951 Filed June 11, 1946 J. ERWOOD ET AL FRICTION CLUTCH AND BRAKE MECHANISM 2 Sheets-Sheet l INVENTORS JOSEPH E ["7000 01442455 E. BECK BY ATTORNEY Jan. 23, 1951 J, woo ET AL 2,539,065

FRICTION CLUTCH AND BRAKE MECHANISM Filed June 11, 1946 2 Sheets-Sheet 2 INVENTORS JOSEPH ERWOOD CHARLES E. BECK BY HONEY Patented Jan. 23, 1951 FRICTION CLUTCH AND BRAKE MECHANISM Joseph Erwood, Chicago, and Charles E. Beck, Park Ridge, 111., assignors to the United. States of America as represented by the Secretary of the Navy Application June 11, 1946,.Ser-ial No. 675,924

I 2 Claims; 1

The present. invention relates to an improved friction clutch mechanism which is suitable for various purposes, one of which is illustrated in the. accompanying drawings as its use as a centrifugal. tester. for mercury switches of the type used with projectile fuzes. As is well known, the standard type. of mercury switch has an in terior porous, barrier or partition which separates. a. contact chamber containing mercury, from an interior sump. In a testin operation, the mercury switch which is to be tested is mounted. in ofl.-centerv position in a rotary carrier while the latter is supported in elevated position with the. driven unit retained by a clutch brake.

With the rotary driving unit in operation at desired speed, the driven unit, with the. carrier, is. depressed; into engagement with the driving unit, and the consequent application of torque to the driven, member imparts spinning movement to. the. switchv carrier similar to the spinning. movement of a projectile when shot from a. gun.

Under. the efiect of centrifugal force created in. the carrier,,. the mercury is removed from the contact. chamber, passed through the porous partition, and deposited in the adjoining sumo with. resultant opening of. the switch. By' the use of a. suitable electrical indicator; the point at which the opening operation of the switch unit from the driving unit, and connecting the driverrunitwith: its brake. After the test, the position of theofi-center switch may be reversed in the carrier, and then, again by means of centrifugal force the mercury may be returned from the. sump... through theporous barrier, into I the contact chamber of the switch. The mechanism is intended to be used in the erect position shown, which aspect lends itself especially wellr to; the arrangement for lubrication herein disclosed.

Therefore, an object of the invention is to provide a friction clutch mechanism of simple and compact construction which is positive in operation, is particularly suitable for use in testing apparatus of the character described above, and embodies a splash-type of lubricating means with which the driven clutch member coacts to periodicallyadmit some of the oil mist to parts otherwise inaccessible to the oil.

These and other objects of the invention may be understood by reference to the accompanying. drawings, in which Fig. 1 is a plan view of a testing assembly in which the invention is embodied;

Fig. 2 is. a front elevation of the device;

Fig. 3 is a vertical, axial sectional. view on a larger scale Fig. 4 is a detail elevational; view of the axially movable, driven clutch unit;

Fig. 5 is a detail elevational view of the fixed friction braking head and Fig. 6 is a detail elevational view of the driving clutch member.

Referring to. the drawings, the. specimen switch. S to be testedis clamped. in off-center position in a conventional chuck C. that performs the functions of a rotary carrier or holder for the switch.

The carrier is rigidly mounted upon the upper end of an upright driven spindle t, and the spindle is journaled in bearings 2 in a vertically reciprocable, substantially non-rotary bushing 3. The. bushing is slidable in a. fixed cylindrical sleeve 4 which is fashioned with an integral cover plate 5. fastened by screws 6 to a. cupshaped cylinder l, and these parts form a fixed housing for the operating. parts of the assembly.

An axially movable rotary driven clutch member is mounted on the lower end of the driven spindle. I, which member projects downwardly into the housing and includes a head 8. secured by pin 9 on the spindle. The head 8 has a frusto-conical. annular flange Ill forming a driven clutch member having both an inner friction face and an outer friction face.

Reciprocating movement is imparted to the driven spindle unit by means of a stud shaft or rock' shaft H having a single axially directed eccentric pin l2 which projects into and coacts with a bearing slot: or socket l3 in the slide bushing 3.. The rock shaft is journaled' in a lateral bearing collar I4 integral with the sleeve 4, and1its rocking movement is limited by means of a set screw. I'5' or equivalent pin radially fixed inthe shaft and movable in. an arcuate slotv Hi'o'f the collar M1 The stud shaft may be rocked manually, or otherwise, by power applied to a crank arm I! rigidly fixed on the shaft, and when it is rocked the bushing 3 moves up or down.

For co-action with the inner friction face of the driven clutch member m, the fixed sleeve 4 is extended into the upper part of the housing 1 where the lower end of the sleeve is reduced in diameter, forming a hollow cylindrical sary clearance.

depending extension on which is mounted a cork friction ring l8 tapered to conform to the inner friction face of the driven clutch member ID and which is occupied by the head 8 with a clearance to form a passageway. As indicated in Figure 3, the fixed ring l8 coacts with the inner friction face of the driven clutch member In as a brake and serves to retain it a ainst rotation when the clutch members are disengaged.

The rotary driven assembly carrying the specimen switch S may be operated by power from a suitable motor indicated at M, and the whole assembly is rigidly mounted on the motor as by screws I9 passed through the bottom wall of the housing I.

On the upper end of the motor shaft 20, which projects upwardly through an open ng in the bottom of the housing i, the driving member 23 of the clutch is mounted by means of an attaching collar 2| and pin 22. The collar is integral with a cup 23 in which is fastened a conical cork ring 24 having an inn r frusto-conical surface shaped to conform to the Shape of the outer surface of the driven clutch member In.

For supplying lubricating oil to the clutch members within the housing I, an a itator or splash lubricator such as a f an ed disc or inverted cup 25. is fixed aga nst the end face of the cup 23 and provided with perimetric agitators in the form of upstanding lugs 25, the function of which is to form an oil mist in the housing. As the driv ng unit of the cl tch rotates, this splash lubricator, passing through oil contained in the housing 1, throws the oil upwardly and sprays the drivin clutch member 23. and when the brake ring I8 is exposed by dis lacement of the driven clutch member ID the oil mist penetrates the passageway throu h the depending portion of the sleeve 4 and lubricates the lower bearing 2.

In operation, after the specimen switch S to be tested has been clamped in the chuck or carrier C, and with the motor-operated driving unit 20 rotating, the crank arm I! in Fig. 2 may be depressed to rock the shaft H and shift the slide bushing 3 with the driven spindle l and clutch member ID to cause engagement of the driven clutch member I 0 with the driving clutch member 23. It will be noted that the pin l2 will prevent rotation of the slide bushing 3 except, of course, for the slight angular shift caused by the motion of the pin itself, that is, the bushing 3 does not take part in the rotat on of the shaft I. The hole I3 that receives the pin l2 may be a cylindrical drilled hole with slightly larger diameter than the pin l2, or may be a short horizontal slot, to provide the neces- After the lapse of a desired time, for transferring the fluent conductor from the contact chamber into the sump of the mercury switch, the crank arm I! is raised to lift the driven clutch member In out of engagement with the driving clutch member 23. The upward movement of the disengaged driven member Ill terminates in frictional contact between the inner frusto-conical friction face of the flange l0 and the cork rin 18, and the latter acts as a brake to retard or stop the rotation of the driven clutch member and its rotary carrier C. If desired, the specimen switch S may now be removed from the chuck, turned end for end, and then replaced and clamped in the chuck or carrier. Then the clutch members [0 and 23 may again be engaged and the driven member I is thus operated to spin the specimen and thereby return the fluent conductor from the sump into the contact chamber of the switch.

What is claimed is:

1. In a friction clutch mechanism, an oil-tight housing including a sleeve having a depending extension on which a brake ring is mounted, a bushing slidable in the sleeve, a rotary driven spindle having at least one bearing in the sleeve and having a head occupying the extension with a clearance to form a passageway and terminating in a driven clutch member engageable with the brake ring, a motor operated drive shaft entering the housing, a driving clutch member on said shaft confronting the driven clutch member, a splash-lubricator revoluble with the driving clutch member, including perimetric agitators for splashing oil in the housing forming a mist to settle on the driving clutch member, and means for sliding the bushing in the sleeve to move the bearing nearer to the passageway and shift the driven clutch member from engagement with the brake ring into engagement with the driving clutch member to provide penetration of the oil mist to the brake ring and through the passageway to the bearing.

2. In a friction clutch mechanism, the combination of an oil-tight housing having a fixed brake rin an erect motor operated drive shaft journaled in the housing, a driving clutch member on said shaft, an annular splash-lubricator mounted on said member in underlying relationship thereto, including perimetric agitators for splashing oil upward in the housing forming a mist to settle on said member, a slide bushing mounted in the housing, a rotary driven spindle journaled in the bushing, a driven clutch member on the lower end of the spindle, said driven clutch member being movable into and out of engagement with said brake ring whereby while so moved out of engagement, the brake ring is exposed to the oil mist, and means for sliding said bushing and the spindle journaled therein alternatively either to engage the driven clutch member with the driving clutch member or to engage said driven clutch member with the brake ring.

JOSEPH ERWOOD. CHARLES E. BECK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Num er Name Date 2,037,644 Voigt Apr. 14, 1936 2,277,275 Swartz Mar. 24, 1942 

